abstract site globals
Merge pull request #2 from benbalter/globals

Abstract site globals
update related posts to be styled better (requires markup changes)
Add 404 page template for GitHub Pages; generalize .lead
fixes #6: don't reset ul and ol padding
remove padding on left of colophon links
Use site.url in atom.xml instead of "http://markdotto.com"
Merge pull request #9 from parkr/patch-1

Use site.url in atom.xml instead of "http://markdotto.com"